Frozen custard machine

ABSTRACT

A relatively compact frozen custard machine is provided. The frozen custard machine includes a housing. The housing is configured to support a first evaporator, a second evaporator, a compressor, and a condenser. The housing is configured to be supported by an elevated surface, such as an existing countertop.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 11/337,209, filed Jan. 20, 2006 entitled “Ice CreamMachine Including a Controlled Input to the Freezing Chamber,” which isa continuation of U.S. patent application Ser. No. 10/654,371, filed byRoss et al. on Sep. 3, 2003, now U.S. Pat. No. 6,988,372, which is acontinuation of U.S. patent application Ser. No. 10/075,089, filed byRoss et al. on Feb. 12, 2002, now U.S. Pat. No. 6,651,448.

The present application is related to U.S. patent application Ser. No.09/639,062 filed Aug. 15, 2000 entitled, “Batch Process and ApparatusOptimized to Efficiently and Evenly Freeze Ice Cream”, which is acontinuation-in-part of U.S. patent application Ser. No. 09/234,970,filed by Ross on Jan. 21, 1999, now U.S. Pat. No. 6,119,472, which is acontinuation-in-part of U.S. patent application Ser. No. 09/083,340,filed by Ross on May 22, 1998, now U.S. Pat. No. 6,101,834, which is acontinuation-in-part of U.S. patent application Ser. No. 08/869,040,filed Jun. 4, 1997, now U.S. Pat. No. 5,755,106, which was acontinuation of U.S. patent application Ser. No. 08/602,302, filed Feb.16, 1996, abandoned. The above-referenced U.S. patent application Ser.No. 09/639,062, U.S. Pat. No. 6,101,834, U.S. Pat. No. 6,119,472, andU.S. Pat. No. 5,755,106 are incorporated herein by reference.

The present application is also related to U.S. application Ser. No.10/074,268, entitled “Ice Cream Machine Including a Secondary CoolingLoop” assigned to the assignee of the present application, filed on Feb.12, 2002 by Ross et al.

FIELD OF THE INVENTION

The present invention generally relates to frozen custard machines orsystems. More particularly, the present invention relates to the overallsize and/or configuration of a frozen custard machine.

BACKGROUND OF THE INVENTION

Ice cream or frozen custard machines, as well as other systems forcooling or freezing food stuffs, condiments, or other materials,typically include an evaporator situated proximate the material beingchilled. For example, in frozen custard machines, liquid custard (e.g.,the mix) is typically inserted in a freezing chamber or barrelassociated with the evaporator and is removed from the barrel as solidor semi-solid frozen custard. The evaporator removes heat from thefreezing chamber as a liquid refrigerant, such as, FREON7, ammonia,R-404a, HP62, or other liquid having a low boiling point, changes tovapor in response to the heat from the liquid mix. Typically, theevaporator is partially filled with vapor as the liquid refrigerantboils (e.g., becomes vapor) in the evaporator.

Quick freezing of liquid mix and high capacity are desirous features offrozen custard machines. In addition, frozen custard quality andefficient manufacture of such custard are dependent upon maintaining aconstant evaporator temperature (e.g., constant barrel temperature). Thebarrel temperature must be kept in a proper range for making frozencustard. If the custard is allowed to become too cold, the liquid mix inthe evaporator becomes highly viscous and can block the travel of thefrozen custard through the barrel. Blockage of the barrel in thefreezing process is commonly known as “freeze up”. If the frozen custardis allowed to become warm, its texture is adversely affected.

Maintaining the temperature of the barrel at a constant level isparticularly difficult as frozen custard flow rates through the machinevary and change the cooling load on the evaporator. For example, moreheat dissipation is required as more frozen custard is produced (i.e.,the flow rate is increased). Additionally, if the barrel temperature istoo low, refrigerant flood-back problems can adversely affect theoperation of the compressor. For example, if the refrigerant is notfully evaporated as it reaches the compressor, the liquid refrigerantcan damage the compressor.

Problems associated with temperature consistency are exacerbated duringperiods of non-production (e.g., an idle mode, a period of slow sales, ahold mode, etc.). Generally, frozen custard machines can experiencenon-production modes, periods of little or low production operation or a“hold” mode. During this mode, liquid mix and frozen custard productremain in the barrel (the cooling chamber) awaiting to be processed.However, due to the low demand for frozen custard, frozen custard is notremoved from the barrel. The frozen custard in the barrel can besubjected to temperature fluctuations during these periods ofnon-production due to heat infiltration.

Heretofore, frozen custard machines have required that the refrigerationsystem (the compressor) be cycled on and off to maintain the frozencustard in the barrel at the appropriate temperature. Such conventionalsystems have been unable to accurately maintain the barrel temperatureat a proper and consistent temperature. For example, the fairly largecompressors associated with the frozen custard machine cool (e.g.,overcool) the barrel down and then allow it to warm back up before thecompressor is engaged to cool the barrel. The temperature within thebarrel fluctuates according to a sawtooth wave. The gradual freezing andthawing causes the product to break down such that texture of theproduct becomes more grainy and less desirable to the taste.

Further, conventional systems have allowed the liquid mix to haveconstant access to the barrel. Generally, conventional systems haveincluded a liquid mix reservoir connected to the evaporator via anaperture. The allowance of liquid mix to enter the barrel duringnon-production times contributes to the warming of the frozen custard inthe barrel, thereby affecting the quality of the frozen custard withinthe barrel when liquid mix is allowed to fill the barrel, the liquid mixcan become frozen against the barrel, thereby reducing the freezingefficiency of the barrel.

Further, conventional systems have allowed the frozen custard product tobe periodically and automatically mixed (i.e., beaten) in the evaporatorduring non-production modes or slow sales periods. Overbeating of thefrozen custard product results in poor frozen custard texture and lessdesirable taste.

Further, conventional frozen custard machines are relatively large unitsthat are supported directly by the ground or floor. The size of frozencustard machines is dictated at least in part by the components of thecooling system provided therein or operatively coupled thereto.Conventional cooling systems require a substantial amount of space andconstitute a substantial amount of weight. Conventional frozen custardmachines are known to be over 5 feet in height and to have weights inexcess of 1000 pounds. Machines of such size are often difficult todeliver, move, clean around, and/or find space for within a store.

Thus, there is a need for a frozen custard machine which can operate ina hold mode and not allow the barrel temperature to fluctuatedrastically. Further still, there is a need for a process and a machinewhich can more efficiently and more evenly cool frozen custard. Evenfurther still, there is a need for a frozen custard machine whichutilizes a barrel and maintains the frozen custard product at aconsistent temperature.

Yet even further still, there is a need for a process or method whichdoes not allow liquid mix to affect the temperature in the barrel whilein a hold or non-production mode. Yet even further, there is a need fora frozen custard machine which does not allow the chamber wall to becomecoated with frozen custard. Further still, there is a need for anevaporator and a control system for a frozen custard machine whichprevents breakdown of the frozen custard product during slow salesperiods. Further, there is a need for a hold mode for a frozen custardmachine which requires little or no bearing of the frozen custardproduct.

Yet even further still, there is a need for a frozen custard machinethat is sized to conveniently fit in a relatively small space within astore (e.g., a frozen custard shop or stand, etc.). Further still, thereis a need for a frozen custard machine that is sized to fit on anelevated surface (e.g., a countertop, tabletop, shelf, etc.) rather thanhaving to be supported by the floor. Further still, there is a need fora relatively compact frozen custard machine that can still output enoughproduct for effective commercial use.

SUMMARY OF THE INVENTION

An exemplary embodiment relates to an ice cream making system. The icecream making system includes an evaporator including a cooling chamberand at least one valve. The cooling chamber has an ice cream input andan ice cream output. The at least one valve is provided at the ice creaminput and is capable of preventing ice cream from entering the coolingchamber.

Yet another embodiment relates to an evaporator for an ice cream makingsystem. The evaporator includes an interior surface defining a coolingchamber for chilling a product, an evaporator chamber and a valve. Thecooling chamber has an ice cream input and an ice cream output. Theevaporator chamber surrounds the cooling chamber. The valve is in serieswith the ice cream input.

Yet another embodiment relates to a method of manufacturing ice cream.The method utilizes an ice cream machine having a cooling chamber. Themethod includes providing liquid ice cream contents into the coolingchamber through a valve. The valve prevents the cooling chamber frombeing more than 75% filled during a hold mode. The method also includescooling the ice cream contents in the cooling chamber and removingfrozen ice cream from the cooling chamber.

Still another embodiment relates to ice cream machine including anevaporator having a cooling chamber. The cooling chamber has an icecream input and an ice cream output. The ice cream machine also includesmeans for restricting access through the ice cream input to the coolingchamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will hereafter be described with reference to theaccompanying drawings, wherein like reference numerals denote likeelements, and:

FIG. 1 is a schematic diagram illustrating an advantageous ice creammaking system according to an exemplary embodiment;

FIG. 2 is a schematic diagram illustrating another advantageous icecream making system according to another exemplary embodiment;

FIG. 3 is a state diagram showing the operation of the systemsillustrated in FIGS. 1 and 2;

FIG. 4 is a more detailed side cross-sectional view of an evaporator foruse in the systems illustrated in FIGS. 1 and 2;

FIG. 5 is a more detailed side planar view of an alternative evaporatorfor use in the systems illustrated in FIGS. 1 and 2;

FIG. 6 is a more detailed side planar view of an alternative evaporatorfor use in the systems illustrated in FIGS. 1 and 2;

FIG. 7 is more detailed side planar view of an alternative evaporatorfor use in the systems illustrated in FIGS. 1 and 2;

FIG. 8 is a general block diagram of a gate, valve and auger controlsystem for the ice cream machine systems illustrated in FIGS. 1 and 2;

FIG. 9 is a flow diagram showing exemplary operation of the systemsillustrated in FIGS. 1 and 2;

FIG. 10 is a perspective view of a frozen custard machine according toan exemplary embodiment;

FIG. 11 is a side planar view of the frozen custard machine shown inFIG. 10;

FIG. 12 is a front planar view of the frozen custard machine shown inFIG. 10;

FIG. 13 is a top planar view of the frozen custard machine shown in FIG.10; and

FIG. 14 is a schematic diagram illustrating a refrigeration or coolingsystem of the frozen custard machine of FIG. 10, shown according to anexemplary embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENT OF THEPRESENT INVENTION

A soft serve, frozen custard, or ice cream machine or making system 10is diagrammatically shown in FIG. 1. Ice cream machine 10 includes acooling or refrigeration system 12 and an evaporator 20. Refrigerationsystem 12 can include any number of components for providing andprocessing liquid refrigerant to and receiving and processing a vaporrefrigerant from evaporator 20. For example only, system 12 can includean expansion device, such as, a valve, a shut-off device, such as, asolenoid valve, a sight glass, a filter, a condenser, a compressor, anaccumulator, and a valve. Although not limited to such systems, system12 can utilize any of the components or systems described in U.S. Pat.Nos. 6,119,472, 6,101,834, 5,755,106, and application Ser. No.09/639,062.

Evaporator 20 can be a system including a number of components on asingle integral unit. For example only, evaporator 20 can include acylindrical cooling tank, a secondary evaporator, and an auxiliary tank.Evaporator 20 can have a design similar to any of the evaporatorsdiscussed in U.S. Pat. Nos. 6,119,472, 6,101,834, 5,755,106, andapplication Ser. No. 09/639,062. Evaporator 20 is modified to include asecondary evaporation or another jacket for maintaining the temperaturewithin evaporator 20 during non-production modes.

Evaporator 20 includes a first refrigerant input 40, a first refrigerantoutput 42, a liquid ice cream input 44, and an ice cream output 46.Evaporator 20 further includes a second refrigerant input 41 and asecond refrigerant output 43. Refrigeration system 12 utilizesrefrigerant input 40 and refrigerant output 42 to provide primarycooling for ice cream making system 10. Refrigerant input 40 and output42 are in fluid communication with an evaporator chamber which surroundsa cooling chamber between ice cream input 44 and ice cream output 46.Output 42 can also be coupled to an auxiliary evaporator tank asdescribed below with reference to FIG. 4.

With reference to FIG. 3, system 10 can manufacture ice cream or otherfrozen or semi-frozen food stuff in an operational mode 61. Ice creamcan be manufactured utilizing a quick draw gate which creates ice creamwhenever gate 52 is opened. During the manufacture of ice cream in mode61, system 10 uses the primary cooling loop associated with input 40 andoutput 42. Alternatively, both the primary evaporator chamber and thesecondary evaporator chamber (the secondary loop associated with input41 and output 43) can be utilized.

When demand ceases, system 10 operates in a non-production mode 62. Whendemand returns, such as, when gate 52 is opened, system 10 returns tomode 61. Various sub-states or intervening states may occur betweenmodes 61 and 62. For example, system 10 may not reach a non-productionmode until the temperature within evaporator 20 reaches a particularlevel. Further, system 10 may be maintained in mode 61 until ice creamis not demanded for a period of time or until the temperature withinevaporator 20 falls below a predetermined level after gate 52 is closed.

Advantageously, when system 10 operates in a non-production mode 62, itmaintains the contents within evaporator 20 at a consistent temperature.Non-production mode 62, such as, an idle mode, or hold mode, refers toany period of time at which system 10 is not allowing ice cream to exitoutputs 46 and yet ice cream product, whether or not completed orpartially completed, remains in the freezing chamber of evaporator 20.The non-production mode can be utilized during periods of slow sales,when system 10 is idling between business hours (system 10 is idle forthe night), etc.

In mode 62, refrigeration system 12 (FIG. 1), second refrigerant input41 and second refrigerant output 43 maintain the interior coolingchamber of evaporator 20 at a consistent temperature. A secondaryevaporator chamber is in fluid communication with input 41 and output43. The secondary evaporator can encompass the primary evaporatorchamber associated with input 40 and output 42.

The secondary evaporator preferably cools refrigerant trapped within theprimary evaporator chamber, thereby acting as a second loop for coolingthe primary refrigeration loop, (the primary evaporator chamber). Thetrapped refrigerant within the primary evaporator surrounding theinterior freezing chamber provides a stabilizing effect to hold andtransfer temperature into the ice cream product held within the interiorcooling chamber.

The refrigeration system 12 can utilize a primary compressor systemand/or a secondary compressor system to provide refrigerant to thesecondary evaporator. The secondary evaporator can be any or anycombination of wrapped tubing, refrigeration jackets, and/or chambers.By maintaining the temperature at a more consistent temperature viarefrigerant input 41 and refrigerant output 43, fluctuations in producttemperature that can break down the ice cream and cause poor tasting icecream are reduced. Further, product which has been left in the interiorchamber for prolonged period of time is not wasted.

In one embodiment in which system 10 is configured as a soft serve icecream machine, ice cream can be stored in the interior chamber withinthe barrel to keep it at the appropriate temperature between draws(e.g., servings). This advantageously allows ice cream to be serveddirectly from evaporator 20 and eliminates the need for a dippingcabinet or other refrigeration unit for storing post manufactured icecream. In this way, ice cream directly from the machine can beimmediately served.

Applicant has found that by using a secondary cooling loop (e.g.,secondary evaporator between input 41 and output 43), a consistenttemperature can be provided in the interior chamber for long periods oftime, such as, 60 hours. Accordingly, over long periods of time innon-production mode 62, the contents of the interior chamber do not needto be emptied and discarded due to on/off cycling. Rather, the contentscan remain in evaporator 20 and be served accordingly. Further, sinceice cream is not discarded, the interior chamber does not need to becleaned after each entry into non-production mode 62.

According to one embodiment, at least one non-positive shutting controlvalve can be provided at input 40 to the primary evaporator. Liquidrefrigerant is allowed to enter through the control valve to evaporator20 (to the first cooling loop of evaporator 20). Allowing liquidrefrigerant through input 40 in a metered but continuous fashion allowsthe liquid in the first stage loop to become saturated and subcooled.The liquid refrigerant completely fills the first stage loop and itspresence acts as a stabilizing effect on temperature swings by means ofthermal mass and thermal transfer.

According to another preferred embodiment, machine 10 can control auger56 at different speeds during different periods of production. Duringproduction of ice cream (mode 61), machine 10 allows auger 56 to spin ata first speed (slow rpm) for production. When gate 52 is open, auger 56spins at a second speed (a faster rpm) for discharging product throughoutput 46. Various speeds can be chosen in accordance with designcriteria to achieve highest production and optimal discharge rates.

System 10 further includes an advantageous ice cream transport controlsystem. Ice cream is provided at ice cream output when a gate 52 isopened. Gate 52 is preferably linked to a valve 54 at ice cream input44. Accordingly, when gate 52 is opened and closed, valve 54 is alsoopen and closed. A delay for opening and closing valve 54 after gate 52is opened can also be implemented by a control mechanism. In oneembodiment, once opened, valve 54 can remain open until a particularcapacity is reached in the cooling chamber.

Valve 54 can be controlled by mechanical linkage coupled to gate 52.Alternatively, an electronic control system can be utilized to controlthe opening of valve 54 with respect to gate 52.

Liquid ice cream is not allowed to enter the interior chamber and warmthe contents of interior chamber when gate 52 is closed and system 10 isin a hold or non-production mode 62 (FIG. 3). In this way, valve 54 onlyallows an appropriate amount of mix to be in the interior chamberaccording to dry barrel technology. Further still, applicants have foundthat by limiting the quantity of material within the interior chamber,system 10 operating as a direct draw machine produces higher qualityfresh ice cream having a superior taste. Product is produced with lowoverrun, thereby operating with results similar to a standard machine.

In another preferred embodiment, machine 10 utilizes valve 54 to meterand limit the amount of product stored in evaporator 20. By eliminatingthe amount of products stored in evaporator 20, the surface areaavailable for production of product is increased, thereby increasing thespeed at which ice cream is frozen. Faster freezing generally results ina better ice cream product texture.

As discussed above, since the amount of custard stored in the barrel ofevaporator 20 is minimized (the heat exchange area is maximized), a moreeffective surface area for production is achieved. This is a significantadvantage over conventional soft serve ice cream machines in whichliquid ice cream product fills evaporator 20 (e.g., the freezing chamberis flooded). With such conventional systems, the inner wall of thechamber is coated with frozen product and becomes less effective forfreezing the remaining product in the chamber of new product.

According to another embodiment, the dry barrel technology discussedabove can be implemented via valve 54. Valve 54 can be a metering valvecontrolled by an actuator. An electric control circuit coupled to asensor can ensure that actuator restricts the chamber to be less thanhalf-filled during non-production modes. Preferably, the freezingchamber in evaporator 20 is 25% to 50% filled with pre-made product. Aconventional machine typically allows of the chamber to be 75 to 100%filled with pre-made product. The metering valve is controlled to bepositively shut when gate 52 is shut and ice cream is not drawn fromevaporator 20. This allows the barrel to store pre-made product but onlyhave 25-50% of the barrel full of pre-made product, thereby resulting infaster freezing of new product.

In addition, a control circuit or system is preferably provided whichprevents an auger 56 within the interior chamber from overbeating thecontents of interior chamber when gate 52 is closed. Embodiments ofcontrol systems mechanisms and schemes for system 10 are described withreference to FIG. 8. The control schemes monitor the operation of auger56 and valve 54.

With reference to FIG. 2, an ice cream making system 100 issubstantially similar to ice cream making system 10. However,refrigeration system 12 of FIG. 1 includes a primary refrigerationsystem 112 and a secondary refrigeration 114. Systems 112 and 114 canshare components. Preferably, systems 112 and 114 have separatecompressors. Alternatively, system 100 can include three or morerefrigeration systems if three or more evaporator chambers or coils areutilized by evaporator 20.

Although evaporator 20 is shown as having four separate interfaces(inputs 40 and 41 and outputs 42 and 43) in FIGS. 1 and 2, theinterfaces can be integrated together and/or separately divided withinevaporator 20. For example, a gate or valve can be used to divertrefrigerant from a single supply line to input 40 and input 41 locatedwithin evaporator 20. Similar systems can be designed for outputs 42 and43.

Primary refrigeration system 112 preferably includes a relatively largecompressor for use in making ice cream during normal operatingtemperatures. A smaller compressor can be utilized in secondaryrefrigeration system 114. The smaller compressor can more efficientlyprovide limited amounts of refrigerant to evaporator 20. Preferably, thesecondary compressor is rated between ¼ and ¾ horsepower, depending ondesign. In a preferred embodiment, a ⅓ horsepower rating is utilized.The primary refrigeration system 112 can utilize a compressor with a 1½to 3 horsepower or more rating. In a preferred embodiment, a compressorrated at a ½ horsepower rating is utilized. The use of the smallercompressor during mode 62 (FIG. 3) reduces energy consumption. Limitersmay be used to make the capacity of a 1½ to 3 HP compressor act likesmaller unit.

In an alternative embodiment, a separate condenser unit can also beprovided for the secondary evaporation chamber and the hopper.

With,reference to FIGS. 4-7, more detailed drawings of alternativeembodiments of evaporator 20 (FIGS. 1 and 2) are shown. Each of theembodiments provides for an evaporator with a primary evaporator chamberand a secondary evaporator chamber. The secondary evaporator chamber isused to advantageously maintain the interior chamber at an appropriatecooling temperature. In FIGS. 4-7, reference numerals having the samelast two digits are substantially similar unless otherwise noted.

With reference to FIG. 4, an evaporator 124 includes an auxiliaryevaporator tank 126, a primary evaporator chamber 128, and a secondaryevaporator 130. Primary evaporator chamber 128 is provided about aninterior cooling chamber 134 which can include an auger such as auger 56(FIG. 1). Chamber 134 can be defined by a 0.125 inch thick stainlesssteel tube 135 having exemplary dimensions of a 4 inch outer diameter.Chamber 128 can be defined by a stainless steel tube 129 havingexemplary dimensions of an inner diameter of 4.5 inches and a length of18 inches-20.5 long.

Chamber 134 includes a liquid ice cream input 142 which can becontrolled by a valve and an ice cream output 144 which can becontrolled by a gate. Preferably, chamber 134 has a volume ofapproximately 226 cubic inches.

Evaporator chamber 128 includes a refrigerant input 152 corresponding torefrigerant input 40 and a refrigerant output 154 corresponding torefrigerant output 42 (FIGS. 1 and 2). Preferably, evaporator chamber128 has a volume of approximately 60 cubic inches (e.g., length of 18inches and a jacket width of 0.25 inches).

Auxiliary tank 126 includes a refrigerant output 156 which can becoupled to refrigeration system 12. Tank 126 operates as an accumulatorsimilar to the accumulator described in U.S. Pat. Nos. 6,119,472 and5,755,106. Tank 126 should not be confused with secondary evaporator 130which operates in parallel with evaporator chamber 128, rather than inseries with chamber 128 as tank 126 operates. Secondary evaporator 130includes a refrigerant input 158 corresponding to refrigerant input 41(FIGS. 1 and 2) and a refrigerant output 160 corresponding torefrigerant output 43. Preferably, secondary evaporator 130 is comprisedof copper tubing wrapped completely around the barrel associated withevaporator chamber 128.

The tubing associated with secondary evaporator 130 can be 3/8 coppertubing. The tubing is closely wrapped in a single layer from end-to-endof evaporator chamber 128. Alternatively, other wrapping configurationsand tubing materials and sizes can be utilized. Evaporator 130 caninclude two or more layers of tubing.

With reference to FIG. 5, an evaporator 224 is substantially similar toevaporator 124 including a refrigerant input 252 and a refrigerantoutput 254. Output 254 can be coupled to system 12 (FIG. 1) or system112 (FIG. 2). Evaporator 224 does not include an auxiliary evaporatortank such as evaporator tank 126 in FIG. 4.

With reference to FIG. 6, evaporator 324 includes a secondary evaporator350. Secondary evaporator 350 is defined by an outer barrel 355, and aninner barrel 360. A primary evaporator chamber 328 is defined by anintermediate barrel 360 and an inner barrel 365. Secondary evaporator350 includes a refrigerant input 370 and a refrigerant output 380.Evaporator 324 can also include an auxiliary evaporator tank such astank 126 (FIG. 4). Inner barrel 365 defines interior cooling chamber334. In a preferred embodiment, inner barrel 365 has an outer diameterof 4 inches and a length of 18 inches. Barrel 360 has an outer diameterof 4.76 inches and a length of 18 inches, and barrel 355 has an outerdiameter of 5.25 inches and a length of 18 inches. Barrels 355, 360, and365 can be 0.125 inches thick and manufactured from stainless steel.

With reference to FIG. 7, evaporator 424 includes secondary evaporator452 including a double wrap of copper tubes. A first wrap 480 isprovided about a second wrap 482. Second wrap 482 is provided aboutevaporator chamber 450. Chamber 450 includes a refrigerant input and arefrigerant to output similar to refrigerant input 352 and 354 (FIG. 6).Wraps 480 and 482 are provided from end-to-end of chamber 450.

Second wrap 482 includes a refrigerant input 490 and a refrigerantoutput 492. First wrap 480 includes a refrigerant input 494 and arefrigerant output 496. Refrigerant input 490 and refrigerant output 492can be coupled to a separate refrigeration system than that used forwrap 480 and chamber 450. Similarly, refrigerant input 494 and output496 can be utilized with a different compressor or refrigeration systemthan that used for wrap 482 and chamber 450. Preferably, wraps 480 and482 are provided on top of each other.

With reference to FIG. 8, a control system 500 is provided to moreaccurately control the temperature and consistency of product withininterior chamber 134 during non-production mode 62. For example, controlsystem 500 can include electronics or mechanical devices to ensure thatvalve 54 is open and closed simultaneously with gate 52. Alternatively,a delay can be utilized between opening and closing gate 52 with respectto valve 54.

Auger 56 is controlled by control system 500 to ensure auger 56 stopswhen the interior cooling chamber within evaporator 20 reaches anappropriate temperature. By sensing the amperage being provided throughthe motor associated with auger 56, the consistency of the contentswithin interior chamber 134 can be determined. The consistency canrepresent the appropriate temperature associated with the contents inevaporator 20. When the amperage is at the appropriate level, controlsystem 500 can turn off the motor which drives auger 56, therebypreventing overbeating of the contents in evaporator 20.

Once gate 52 is opened, the motor can be reset and allowed to run untilgate 52 is closed. After gate 52 is closed, the motor will continue torun until current sensed through the motor indicates that theappropriate temperature in interior chamber 134 is reached.Alternatively, control schemes can be utilized to stop auger 56appropriately. For example, system 500 can utilize a temperature sensorsituated in chamber 502 or chamber 134. Preferably, control system 500includes a micro switch or other device for sensing when gate 46 isopened to re-engage the motor which drives auger 56.

With reference to FIG. 9, the various modes associated with systems 10and 100 described with references to FIGS. 1 and 2 are discussed. In afirst mode, or production mode 602, manufacture of an ice cream productcan begin. Generally, the production mode operates auger 56 and uses aprimary evaporator associated with refrigeration input 40 andrefrigeration output 42. An operator can open gate 46 and remove icecream from evaporator 20 in an operational mode 604. When gate 52 isopen, valve 54 is open, thereby allowing liquid ice cream intoevaporator 20. After gate 46 is closed and valve 44 is closed, system 10can enter a non-production mode 606.

Non-production mode 606 can occur once the temperature within evaporator20 reaches a particular temperature. In mode 606, the primary evaporatorand auger are utilized. Similarly, as ice cream is removed, the augerand primary evaporator are utilized. In mode 606, the secondaryevaporator is utilized and the auger is stopped to prevent overbeatingof the ice cream.

Referring to FIGS. 10 through 14, a frozen custard machine or ice makingsystem 700 is shown according to an exemplary embodiment. Unlikeconventional frozen custard machines, frozen custard machine 700 is nota standalone or floor model system, but rather is a relatively compactsystem designed to be supported by an elevated surface such as acounter, table, cabinet, or any other suitable worksurface. The heightat which frozen custard machine 700 is supported from the ground orfloor may vary depending on the particular application, but preferablyit is supported at a height that is convenient for an operator to use.For example, it may be desirable to support frozen custard machine 700at a height above 24 inches from the floor, and preferably at a heightranging between approximately 30 inches and approximately 40 inches fromthe floor.

Referring to FIGS. 10 through 13 in particular, the components of frozencustard machine 700 are contained within a housing 702. Housing 702 isshown as a substantially rectangular structure having a width 704, aheight 706, and a depth 708. According to an exemplary embodiment, width704 is between approximately 15 inches and approximately 30 inches,height 706 is between approximately 20 inches and approximately 50inches, and depth 708 is between approximately 18 inches andapproximately 35 inches. According to a preferred embodiment, width 704is approximately 20 inches, height 706 is approximately 35 inches, anddepth 708 is approximately 25 inches. Providing housing 702 within suchdimensions advantageously allows frozen custard machine 700 toconveniently fit on a preexisting elevated worksurface. According tovarious alternative embodiments, housing 702 may be configured in any ofa variety of shapes, having any of a number of dimensions, which providefor a machine that can be readily supported by an elevated surface.

Housing 702 is preferably formed of an internal frame structure (notshown) made of a rigid material, such as steel, which is covered by oneor more panels 710. The frame structure is configured to support thevarious components of frozen custard machine 700, while panels 710 areconfigured to conceal the components supported within the framestructure. According to the embodiment illustrated, housing 702 includesa front panel 712, a pair of side panels 714, a top panel 716, and arear panel 718. Preferably, panels 710 are formed of a relatively rigidmaterial that is resistant to corrosion and is relatively easy to cleanor sanitize. According to one embodiment, panels 710 are formed ofstainless steel and a welded to the frame structure and/or the otherpanels. According to another embodiment, panels 710 are covered with acoating and are coupled to the frame structure using one or morefasteners (e.g., rivets, bolts, etc.). Such an embodiment may providesufficient cost savings since the welding process and finishing process(e.g., grinding, etc.) may be eliminated.

Preferably, frozen custard machine 700 has an overall weight that allowsit to be placed upon a worksurface without having to modify (e.g.,reinforce, etc.) the worksurface. The overall weight of frozen custardmachine 700 is significantly less than the overall weight ofconventional frozen custard machines (i.e., standalone machinesconfigured to be supported by the floor). According to an exemplaryembodiment, frozen custard machine 700 has an overall weight (withoutcustard and/or the liquid mix) between approximately 200 pounds andapproximately 400 pounds. According to various alternative embodiments,frozen custard machine 700 may have an overall weight which is greateror less than the range provided.

Frozen custard machine 700 is diagrammatically shown in FIG. 14. Frozencustard product is formed within a first evaporator 720 from a liquidmix provided to first evaporator 720 from a second evaporator 750. Firstevaporator 720 can have any of a number of configurations, including,but not limited to, those discussed above and those discussed in U.S.Pat. Nos. 6,119,472, 6,101,834, 5,755,106, and application Ser. No.09/639,062. According to the embodiment illustrated, first evaporator720 includes a primary refrigeration loop having a first refrigerantinput 722 and a first refrigerant output 724, a secondary refrigerationloop having a second refrigerant input 730 and a second refrigerant,output 732, a liquid mix input 726, and a frozen custard output 728.

Frozen custard machine 700 utilizes first refrigerant input 722 andfirst refrigerant output to provide primary cooling of a cooling chamber734 wherein the liquid mix is transformed into frozen custard. Firstrefrigerant input 722 and first refrigerant output 724 are in fluidcommunication with an evaporator chamber 736 which surrounds coolingchamber 734. According to the embodiment illustrated, an auxiliaryevaporator tank 736 is provided between evaporator-chamber 736 and firstrefrigerant output 724. Auxiliary evaporator tank 736 may have any of avariety of configurations including, but not limited to, those discussedin U.S. Pat. No. 6,119,472.

Frozen custard machine 700 utilizes second refrigerant input 730 andsecond refrigerant output 732 to provide cooling of cooling chamber 734during a non-production mode (e.g., an idle mode, a hold mode, etc.) inwhich frozen custard machine 700 is not allowing frozen custard to exitfrozen custard output 728 and yet frozen custard product (whether or notcompleted or partially completed) remains in cooling chamber 734. Secondrefrigerant input 730 and second refrigerant output 732 are in fluidcommunication with a secondary evaporator chamber 738. Secondaryevaporator chamber 738 may be provided under, over, and/or adjacent toevaporator chamber 736. Preferably, secondary evaporator chamber 738cools refrigerant trapped within evaporator chamber 736. According to analternative embodiment, the secondary refrigeration loop may utilize thesame chamber as the primary refrigeration loop using a series of valvesor other control systems.

First evaporator 720 further comprises a structure, shown as a barrel740, having an interior surface, wall or tube 742 which defines coolingchamber 734. Tube 742 of barrel 740 may be formed of a variety ofsuitable materials, such as stainless steel. According to an exemplaryembodiment, barrel 740 is a cylindrical member having an overall lengthbetween approximately 8 inches and approximately 20 inches and an innerdiameter between approximately 3 inches and approximately 6 inches.According to a preferred embodiment, barrel 740 has an overall length ofapproximately 12 inches and an inner diameter of approximately 4 inches.Utilizing a barrel of this size, advantageously allows frozen custardmachine 700 to be configured as a relatively compact unit. Theefficiency of the refrigeration system discussed above advantageouslyallows a shorter barrel 740 to be used for frozen custard machine 700.According to various exemplary embodiments, barrel 740 may havedimensions greater or less than those provided so long as barrel 740 canfit within a frozen custard machine configured to be supported by anelevated surface (such as a counter). One or more barrels 740 may besupported within housing 702. Providing more than one barrel 740 mayallow frozen custard machine 700 to simultaneously produce more than onefavor of frozen custard product.

Supported within barrel 740 is an auger 744. Auger 744 is provided tomix or otherwise agitate the liquid mix and/or frozen custard productwithin barrel 740. Auger 744 generally comprises a shaft upon which oneor more paddles or blades are supported. The blades are preferablyshaped and sized to facilitate the mixing of the liquid mix withinbarrel 740, the scraping of frozen custard product from tube 742, andthe movement of frozen custard product out of barrel 740. The blades arepreferably formed of a low friction material, such as Delrin, but may beformed of any of a variety of suitable materials. A first end of theshaft is operatively coupled to a motor 746 configured to providerotational movement to the shaft and subsequently the blades. Operationof motor 746 is preferably coupled to a control system (as discussedabove) and/or a user interface allowing for manual control. Motor 746 issupported within housing 702 of frozen custard machine 700.

As mentioned above, liquid mix is provided to first evaporator 720 fromsecond evaporator 750. Second evaporator 750 can have any of a number ofconfigurations. According to the embodiment illustrated, secondevaporator 750 includes a refrigerant input 752 and a refrigerant output754, a liquid mix input 756, and a liquid mix output 758. Frozen custardmachine 700 utilizes refrigerant input 752 and refrigerant output 754 toprovide cooling of the liquid mix before the liquid mix is provided tofirst evaporator 720. Preferably, the liquid mix is maintained in secondevaporator 750 at approximately 34 degrees Fahrenheit, but any of avariety of temperatures may be maintained for a particular applicationif desired.

Refrigerant input 752 and refrigerant output 754 are in fluidcommunication with an evaporator chamber 760 which surrounds areceptacle, shown as a hopper 762, configured to retain the liquid mixuntil the liquid mix is provided to first evaporator 720. Hopper 762 hasa substantially open top which constitutes liquid mix input 756. Theopen top configuration advantageously allows the liquid mix to be addedeasily to hopper 762 by simply pouring the liquid mix into the open topof hopper 762. Referring back to FIG. 10, housing 702 includes a movableand/or removable portion (shown as a lid 717) in top panel 716 whichcovers the open top of hopper 762. An operator may selectively move lid717 to gain access to the open top of hopper 762.

Referring again to FIG. 14 and according to the embodiment illustrated,hopper 762 is supported above first evaporator 720 within housing 702.Liquid mix retained in hopper 762 is added to barrel 740 as needed(e.g., as frozen custard product is dispensed from frozen custard output728, etc.). Supporting hopper 762 above first evaporator 720advantageously allows the liquid mix to be added to barrel 740 withoutthe use of a pump. In such a embodiment, frozen custard machine 700relies on gravity to feed the liquid mix into barrel 740. Not requiringa pump for the liquid mix may save space within the compact system.According to various exemplary embodiments, hopper 762 may be supportedin any of a number of positions relative to first evaporator 720 and apump may be provided to pump the liquid mix into barrel 740. Preferably,a valve (not shown) is provided between liquid mix output 758 and liquidmix input 726 of first evaporator 720. Such a valve controls the rate atwhich the liquid mix is added to barrel 740.

According to the embodiment illustrated, hopper 762 is supportedentirely within housing 702. To provide for this configuration, hopper762 has a reduced capacity. According to an exemplary, hopper 762 isconfigured to hold between approximately 1 gallon of liquid mix andapproximately 5 gallons of liquid mix. According to a preferredembodiment, hopper 762 is configured to hold approximately 3 gallons ofliquid mix. According to various alternative embodiments, hopper 762 mayextend at least partially out of housing 702 and/or may be configured tohold more or less liquid mix than the amounts provided herein by way ofexample.

Referring further to FIG. 18, frozen custard machine 700 is furthershown as including a compressor 770 and a condenser 772. Compressor 770and condenser 772 are each supported within housing 702. Compressor 770provides high pressure vapor refrigerant to condenser 772, which in turnprovides high pressure liquid refrigerant through a sight glass 774 to amanifold 776 comprising one or more expansion devices. Sight glass 774allows an operator to determine visually if the level of high pressureliquid refrigerant in first evaporator 720 and/or second evaporator 750is low, requiring additional refrigerant to be added to the system.

Frozen custard machine 700 preferably utilizes a relatively smallcompressor 770 to operate first evaporator 720 (comprising tworefrigeration loops) and second evaporator 750. The use of a smallercompressor 770 reduces the space occupied by compressor 770 withinhousing 702 and reduces the overall weight of compressor 770. Reducingboth factors enables frozen custard machine 770 to be sized to fit on anelevated surface. Further, using a smaller compressor may also reduceenergy consumption. According to an exemplary embodiment, compressor 770has a rating of less than 3 horsepower. According to a preferredembodiment, compressor 770 has a rating of approximately 1 horsepower.

According to the embodiment illustrated, manifold 776 includes a singleinput 778 coming from condenser 772 and three outputs (a first liquidrefrigerant output 780, a second liquid refrigerant output 782, and athird liquid refrigerant output 784). First liquid refrigerant output780 is in fluid communication with first refrigerant input 722 of firstevaporator 720, second liquid refrigerant output 782 is in fluidcommunication with second refrigerant input 730 of first evaporator 720,and third liquid refrigerant output 784 is in fluid communication withrefrigerant input 752 of second evaporator 750. An expansion device,shown as an expansion valve 786, is provided at each of the three liquidrefrigerant outputs. Expansion valves 786 establish a relatively lowpressure level for the liquid refrigerant passing into first refrigerantinput 722, second refrigerant input 730, and refrigerant input 752respectively.

Similar to the embodiments discussed above, frozen custard machine 700is configured to operate between a production mode and a non-productionmode. Frozen custard machine 700 may incorporate any of the abovediscussed control systems for determining when to operate in aparticular mode or may incorporate any other suitable system for thisfunction. In the production mode, frozen custard machine 700 isconfigured to provide a continuous stream of frozen custard product.While the output rate of frozen custard product will vary depending uponthe particular liquid mix, frozen custard machine is configured tooutput between approximately 3 gallons and approximately 6 gallons perhour during a typical production mode. According to various alternativeembodiments, frozen custard machine 700 may be configured to output moreor less frozen custard product than the rates provided herein.

According to the embodiment illustrated, a ribbon of frozen custardproduct is directed by a chute 703 (shown as outwardly extending atfront panel 712 in FIG. 10) or other structure as it passes throughfrozen custard output 728. A cut off gate may be provided at frozencustard output 728 to cut or other stop the flow of frozen custardproduct. An optional dipping cabinet 705 may be provided below chute 703to collect and store the frozen custard product. Frozen custard productmay then be hand dipped from dipping cabinet 705 for serving tocustomers. According to various alternative embodiments, frozen custardmachine 700 may be a direct draw machine wherein frozen custard productis taken directly from the machine for serving to the customers.

The term “coupled”, as used in the present application, does notnecessarily mean directly attached or connected. Rather, the term“coupled” in the present application means in fluid or electricalcommunication there with. Two components may be coupled together throughintermediate devices. For example, the evaporator input is coupled tothe condenser output even though the expansion valve, accumulator/heatexchanger, and sight glass are situated between the evaporator input andthe condenser output.

It is understood that, while the detailed drawings and specific examplesgiven to describe the preferred exemplary embodiment of the presentinvention, they are for the purpose of illustration only. The apparatusof the invention is not limited to the precise details and conditionsdisclosed. For example, although food stuffs and frozen custard arementioned, the invention may be utilized in a variety of refrigerationor cooling systems. Further, single lines for carrying liquidrefrigerant can represent multiple tubes. Additionally, although aparticular valve, accumulator, compressor, condenser, and filterconfiguration is shown, the advantageous machine can be arranged inother configurations. Further still, the evaporator barrel and freezercan have any number of shapes, volumes, or sizes. Various changes can bemade to the details disclosed without departing from the spirit of theinvention, which is defined by the following claims.

1. A frozen custard machine comprising: a housing; a first evaporatorsupported within the housing, the first evaporator including a coolingchamber, the cooling chamber having a length less than 20 inches; asecond evaporator supported within the housing, the second evaporatorincluding a hopper configured to hold a liquid mix; and a compressorsupported within the housing, the compressor having a horsepower ratingof less than 3 horsepower; wherein the housing is configured to be,supported on an elevated worksurface.
 2. The frozen custard machine ofclaim 1, wherein the cooling chamber includes a liquid mix input influid communication with the hopper and a frozen custard product output.3. The frozen custard machine of claim 2, further comprising a gate atthe frozen custard product output and at least one valve is provided atthe liquid mix input, the valve allowing liquid mix to enter the coolingchamber and the valve preventing the liquid mix from entering thecooling chamber, the valve including a control input.
 4. The frozencustard machine of claim 3, further comprising a control system coupledto the control input, the control system ensuring that the coolingchamber is not more than 50 percent filled when the gate is closed. 5.The ice cream making system of claim 4, wherein the valve is controlledto maintain the cooling chamber filed to 25-50 percent.
 6. The frozencustard machine of claim 1, wherein the first evaporator includes afirst evaporator chamber and a second evaporator chamber surrounding thecooling chamber, the second evaporator being used during anon-production mode.
 7. The frozen custard machine of claim 6, whereinthe compressor is operatively coupled to both the first evaporatorchamber and the second evaporator chamber.
 8. The frozen custard machineof claim 7, wherein the second evaporator includes an evaporator chamberfor cooling the hopper.
 9. The frozen custard machine of claim 8,wherein the compressor is operatively coupled to the evaporator chamberof the second evaporator.
 10. The frozen custard machine of claim 9,wherein the compressor does not exceed a power rating of 1 horsepower.11. The frozen custard machine of claim 1, wherein the length of thecooling chamber is less than 15 inches.
 12. The frozen custard machineof claim 1, wherein the housing has a height less than 48 inches, adepth less than 30 inches and a width less than 25 inches.
 13. Thefrozen custard machine of claim 1, wherein the frozen custard machinehas an overall weight of less than 500 pounds.
 14. A frozen custardmachine comprising: a housing; a first evaporator supported within thehousing, the first evaporator including a cooling chamber; a secondevaporator supported within the housing, the second evaporator includinga hopper configured to hold a liquid mix; and a compressor supportedwithin the housing, the compressor operatively coupled to the firstevaporator and the second evaporator and having a horse power rating ofless than 3 horsepower; wherein the first evaporator is configured tooutput between approximately 3 gallons and 6 gallons of frozen custardan hour, wherein the housing is configured to be supported on anelevated worksurface.
 15. The frozen custard machine of claim 14,wherein the housing has a height less than 48 inches, a depth less than30 inches and a width less than 25 inches.
 16. The frozen custardmachine of claim 14, wherein the frozen custard machine has an overallweight of less than 500 pounds.
 17. The frozen custard machine of claim14, wherein the first evaporator includes a first evaporator chamber anda second evaporator chamber surrounding the cooling chamber, the secondevaporator being used during a non-production mode.
 18. The frozencustard machine of claim 17, wherein the second evaporator includes anevaporator chamber for cooling the hopper.
 19. A frozen custard machinecomprising: a housing having a height less than 48 inches, a depth lessthan 30 inches, and a width less than 25 inches; a first evaporatorsupported within the housing, the first evaporator including a firstevaporator chamber and a second evaporator chamber; a second evaporatorsupported within the housing, the second evaporator including a hopperconfigured to hold a liquid mix; and a compressor supported within thehousing; wherein the housing is configured to be supported on anelevated worksurface.
 20. The frozen custard machine of claim 19,wherein the first evaporator is configured to output between 3 gallonsand 6 gallons of frozen custard product an hour during a productionmode.